It's not just golf balls that are getting teed off around the Pebble Beach Company these days.

The California Coastal Commisioners are challenging a plan to build a championship 18-hole golf course and driving range as well as homes, hotels and conference facilities proposed by the company owned by actor-director Clint Eastwood, former baseball commissioner Peter Ueberroth and golf legend Arnold Palmer.

It's the latest twist in a development story that has dragged on for years, involved a Monterey County referendum in 2000 and pits environmentalists versus developers in a debate over who cares more about preserving the natural beauty of the area's signature Monterey Pine forest.

Monterey County Supervisors unanimously approved the project last year, but several environmentalist groups, including the Sierra Club, filed appeals to the plan's provisions last summer with the state Coastal Commission.

Pebble Beach Co.'s previous owner -- Taiheiyo Club Inc., a Japanese company -- had proposed building another course as well as hundreds of new homes before selling the company for $850 million in 1999.

The new owners "down-zoned the property to its current proposed plan from 900 homes to 34 homes, a hotel and golf course and offered an additional 400 acres to be preserved with the 500 acres they had already agreed to give up," said Anthony Lombardo, an attorney for Pebble Beach Co.

"When the new owners bought this company, they were competing against other buyers that had an exit strategy in place, parcel by parcel," said Mr. Lombardo. "The new owners have always wanted to keep Pebble Beach Co. together and preserve as much land as possible. Altogether, they are preserving 1,400 acres of land."

The Del Monte Forest Preservation and Development Plan would also add 2.5 miles of new trails and road improvements as well as upgrades to the 17-Mile Drive intersection.

The project, which outlines plans for underground parking at the Pebble Beach Lodge and Spanish Bay, also calls for moving the equestrian center, now near the lodge, to the site of a former sand mining pit at Sawmill Gulch.

During a marathon March 9 hearing, members of the California Coastal Commission said they were against moving the equestrian center to Sawmill Gulch, which has had a scenic easement placed on it since 1982, when Spanish Bay was constructed.

In fact, Pebble Beach Co. had agreed to restore the land at the 45-acre Sawmill Gulch and conserve the sand pit after using it to mine Spanish Bay.

"This is an area of forest that is protected by a legal instrument that was put in place when Spanish Bay was approved," said Sarah Christie, a legislation coordinator with the California Coastal Commission.

The proposal also includes building the new golf course in an area that would cut through the heart of the Monterey Forest between Pebble Beach Golf Links and the Cypress Point Golf Club, which would negatively impact environmentally sensitive habitat, according to coastal commissioners.

"The Coastal Commission has been unambiguous since the beginning about this project," said Ms. Christie. "The Coastal Act protects environmentally sensitive areas and the area we're talking about is entirely sensitive habitat. We don't see any way you can build a golf course in the area without negatively impacting this protected habitat."

Coastal officials worry the new project will threaten wetlands, dunes and dozens of rare and endangered species, such as the California red-legged frog. Developers will have to chop down more than 16,000 trees to make room for the project, which they say could eliminate any chances of finding a cure for a rare tree disease -- Pitch Canker -- found in Monterey pines.

"It is so important to protect the native trees," said Ms. Christie. "Invariably, some of these trees will be resistant to the disease and that could be essential to finding a cure."

Mr. Lombardo called the Monterey Pine the "most prevalent" tree in the world, estimating there are 50 million in California and 4 billion around the world. "We're talking about trees that only live to be 80 years old and are no bigger than 4 inches in diameter."

Even so, environmentalists contend that Monterey is home to only one of five native Monterey Pine tree stands in the world and could possibly play a role in finding a cure for the fungus.

While researchers agree, they say the fears about tree mortality rate over Pitch Canker were overly dramatic. In fact, during an eight-year study in Monterey, the task force estimated that the mortality rate was only 5 percent.

"It's definitely a significant issue, but certainly not to the degree we once thought it was," says Steven Staub, co-chair of the California Pitch Canker Task Force. "The Monterey Pine is the most widely planted timber tree in the world and we want to make sure we don't narrow the genetic base of the tree."

"My sense is that the Coastal Commission would love to try to accommodate Pebble Beach Co. and would approve zoning changes that would allow them to build perhaps 200 new hotel rooms that could be valued at hundreds of millions of dollars," says Mr. Massara. "They could do it without cutting down any trees. In my opinion, Pebble Beach Co. has to come to grips with the fact that they can do a $200 million project, but not a $500 million dollar project."